Nuclear orientation Nuclear orientation , in nuclear physics , is the directional ordering of an assembly of nuclear spins with respect to some axis in space. It is one of the nuclear spectroscopy methods.
A nuclear level with spin in a magnetic field will divide into magnetic sub-levels with an energy spacing.
The populations of these levels are determined by the Boltzmann distribution at a steady temperature and will essentially be equal. The exponential in the Boltzmann distribution should not be equal to 1 to obtain unequal populations. To achieve this, cooling to a temperature of around 10 millikelvin is needed.
Typically, this is achieved by implanting the nuclei of interest into ferromagnetic hosts.
In the mid-1940s, Yevgeny Zavoisky developed electron paramagnetic resonance , eventually leading to the concept of nuclear orientation.
In the early 1950s, Neville Robinson , Jim Daniels , and Michael Grace produced an example of nuclear orientation for the first time at the Clarendon Laboratory , University of Oxford .
There is now a Nuclear Orientation Group at Oxford.
Bibliography
K. S. Krane, Nuclear orientation and nuclear structure . Hyperfine Interactions doi : 10.1007/BF02398283
B. Bleaney, Cross-relaxation and nuclear orientation in ytterbium vanadate . Proceedings: Mathematical, Physical and Engineering Sciences The Royal Society .
B. Bleaney, Dynamic nuclear polarization and nuclear orientation in terbium vanadate . Applied Magnetic Resonance doi : 10.1007/BF03162437 References
↑ Nuclear orientation , The Free Dictionary ↑ Nuclear orientation Archived 2011-06-17 at the Wayback Machine AccessScience 1 2 General Idea of Nuclear Orientation , Nuclear Orientation Group , University of Oxford , UK.↑ B. Bleaney and O. V. Lounasmaa, Nuclear Orientation and Nuclear Cooling Experiments in Oxford and Helsinki. Part 2. Progress from 1945 to 1970 . Notes and Records of the Royal Society of London The Royal Society . ↑ Nicholas Kurti, Obituary: Neville Robinson [ dead link ] The Independent